BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Bufflehead In Northern Rockies

All regionsNorthern RockiesWaterfowl

Bufflehead in Northern Rockies has surged: up 223% on the route-weighted index since 1981.

+223%Since 1981TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
28Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
41YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Bufflehead has surged in Northern Rockies: up 223% on the route-weighted index since 1981.

Bufflehead In Northern Rockies Population Forecast

If the recent trend holds, Bufflehead in Northern Rockies is projected to stay roughly flat through 2029, near 0.14 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±34.3%, with 80% of held-out values landing inside the 95% band.

-5%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.14Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.3395% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±34.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Bufflehead in Northern Rockies is projected to stay roughly flat through 2029, near 0.14 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±34.3%, with 80% of held-out values landing inside the 95% band.19742029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.140.000.33
20260.140.000.33
20270.140.000.33
20280.140.000.33
20290.140.000.33

Routes In Northern Rockies

Routes recording Bufflehead in Northern Rockies.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Hebgen LakeMONTANA162024
YellowstoneWYOMING92022
Salmon RiverIDAHO82002
Hayden ValWYOMING71985
NaplesIDAHO62016
Neponset ResUTAH52010
Red RockMONTANA41995
Lolo PassIDAHO32019
St MaryMONTANA22008
Wise RiverMONTANA22007
St. Mary 2MONTANA22024
East Glacier ParkMONTANA22024
NorthportWASHINGTON22021
MammothWYOMING22006
CabartonIDAHO12023
BurgdorfIDAHO12003
KalispellMONTANA12012
AugustaMONTANA12022
ClancyMONTANA12023
Inside RoadMONTANA12005
Summit PrOREGON12023
NewbridgeOREGON12024
LaurierWASHINGTON12010
Ne EntranceWYOMING11999
Hunter PeakWYOMING12006

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.